Answer
The equation matches with the graph labeled as II.
Work Step by Step
It has the equation of a parabola with vertical axis: $x^2=4py$
$x^2=-6y$
$4p=-6$
$p=-\frac{3}{2}$
$p\lt0$. Parabola opens downwards.
When $y=-1$
$x^2=-6(-1)=6$
$x=±\sqrt 6\approx±2.45$
So, the parabola passes through the points $(±2.45,-1)$
The equation matches with the graph labeled as II.